The present invention relates generally to improvements in solar energy collection systems and more particularly pertains to new and improved sun-tracking solar energy collection systems that are capable of producing high solar energy concentration ratios.
The overriding problem confronting developers of solar energy power systems has been the problem of producing the required high temperatures at a cost that would make the utilization of solar power competitively attractive. Presently, systems capable of producing the required high temperatures directly from solar energy utilize tracking devices with large moving primary reflectors. Accurate tracking devices, however, are expensive to construct and costly to maintain if they are to track under conditions of weather extremes and varying high wind forces. The cost of producing large tracking reflectors and the costs of an associated tracking mechanism sturdy enough to withstand expected wind forces make a solar energy heat generating plant that can provide sufficient power to produce electricity in the multi-megawatt range an uneconomical prospect.
Solar energy collection systems that are to be used for producing superheated steam for use by steam-driven generator equipment for generating electric power must be capable of transforming solar energy into thermal energy in the range of 1000.degree. F. or higher. The prior art systems capable of such heat generation involve tracking concentrators such as three-dimensional paraboloidal dishes which can be precisely steered in both altitude and azimuth to follow the sun's movement. In order to generate temperatures in the range of 1000.degree. F. in sufficient quantity for use as energy for the generation of electrical power, literally thousands of 20-foot diameter, three-dimensional parabolic dishes must be utilized. The cost of producing large numbers of such optically finished compound curve reflecting surfaces that are sturdy enough to hold their figure when tilted and turned in the wind is prohibitive.